has anyone tried this one in wet conditions? I know the Bora is quite water resistant(almost proof), but would you advise a packcover with this one?

At 9 oz, the weight of ArcTeryx's pack cover meets or exceeds the weight of waterproof stuff bags, which are a much more failsafe method for keeping key items dry.

Even the Bora was not totaly waterproof, but with the water resistant zippers it was better than the Altra Series. The pack's material is waterproof, but the zippers aren't. I put my gear in roll top waterproof bags, and carry a rain cover too. If you are looking for a totaly waterproof pack that has the same suspension take a look at the Arcteryx Naos 70 or Arrakis 65. In regards to Hudson Hiker's comments about this pack and materials not being durable. I have this pack and find it's materials and construction to be superior to other packs on the market. When compared to the Bora series the construction is different, but I don't feel it is inferior. The pack has very thick material in all of the high wear areas, and even has some foam padding sandwitched between two layers of material on the bottom of the pack. I my opinion it would take much effort to rub a hole in this pack, and it sounds like it was either a manufacturing defect or misuse. The pack carries a lifetime warranty, but they won't cover damage from abuse.

This is NOT a waterproof pack and if you are going to be in a rainy climate you will need a rain cover. One day in Scotland rain and the result was a damp down sleeping bag due to the U-zipper and a wet pack towel in the kangaroo pocket that does not have a water tight zipper either. I had to buy a pack cover before I began a trek into the snow covered Sierras in California and got nervous and bought a waterproof stuff-sack for my down sleeping bag. My gear has now stayed dry but I was very disappointed with this aspect of this pack and the durability of the pack material (cloth) is failing after only about 30 days of backcountry use (a couple of holes rubbed through just from normal use)

Since this pack was designed and tested in Vancouver,BC, it's built to be very water-resistant. Fabrics use silicon and urethane to stabilize fabrics and make them very water resistant. Stitching and zippers are not water proof, so if you'll be in really wet conditions, a pack cover is recommended. http://www.backcountry.com/outdoorgear/Arcteryx-Backpack-Cover/ARC0287M.html